Ladder structure



May 27, 1952 w. T. MASON LADDER STRUCTURE}v 2 SHEETS-SHEET 1 Filed March '7, 1946 Inventor -W2'IZza*m 7f777asorz- May 27, 1952 w. T. MASON LADDER STRUCTURE 2 SHEETS-SHEET 2 Filed March 7, 1946 William T 7f/a6'021-- II Ib'II/IIIIIIIIIIIL Patented May 27, 1952 UNITED STATES PATENT @FFHCE mesne assignments, to Louisville; Metal Products Company, Louisville, Ky., a corporation of Kentucky Application March '7, 1946, Serial No. 652,651 7 Claims. (01. 228-56) This invention relates to new and useful improvements and structural refinements in ladders, more particularly, to a novel assemblage of light weight parts into a simple and an easily portable ladder structure, such as may be employed with relatively greater utility and with substantially increased convenience, for the purpose for which it is intended.

A further object of the invention is to provide a ladder structure of considerable strength, neat appearance, and in other Words, a structure which will surpass in all respects, the present conception of conventional ladders and the clumsiness, effort and general inconveniences associated with the use of the same.

Another object of the invention is to provide a ladder structure which cannot easily become damaged and which, by virtue of its simplicity willlend itself easily to economical manufacture.

With the above more important objects in view, and such other objects as may become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts as illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of the invention;

Figure 2 is a side view thereof;

Figure 3 is a cross-sectional view, taken in the plane of the line 3-3 in Figure 2;

Figure 4 is a crosssectional view, taken in the plane of the line 44 in Figure 1;

Figure 5 is a fragmentary, cross-sectional view, taken in the plane of the line 5-5 in Figure 2, and

Figure 6 is a cross-sectional view, taken in the plane of the line 56 in Figure 1.

Like characters of reference are used to designate like parts in the specification and throughout the several views.

Referring now to the accompanying drawings in detail, the invention consists of a plurality of ladder sections designated generally by the reference character IQ, each comprising a pair of spaced, parallel side rails i I, open at their relative inner sides and defining a substantially U-shaped cross sectional configuration.

Each of the side rails H consists of a pair of spaced, parallel angle bars [2, the same being rigidly secured together by means of a plurality of flat webs or gusset plates l3. These plates are mounted against the inner surface of one arm of each of the angles 52 by any suitable means, such as rivets I4, as will be clearly apparent from the accompanying drawings.

Each of the gusset plates i3 is formed substantially at the center thereof with an aperture 55 provided with a countersink 16, the purpose of which will be hereinafter more fully described.

The essence of the invention resides in the provision of a plurality of tubular rungs ll which extend between the side rails I l, and in the manner in which said rungs are connected to the side rails, which is now to be described.

The rungs H are open ended, and a tubular plug 13 is inserted into each end thereof, as, is best illustrated in Figures 4 and 5. Each plug is secured in position by means such as a rivet 52 extending transversely through the rung and the plug, and a portion of the latter protrudes from.

the end of the rung and through the aperture it of the gusset plate It.

The protruding end of the plug is is flared into the countersink l6 and is peened over against the surface of the plate It to form a rivet-like shoulder 23, as will be clearly apparent from the accompanying drawings, thus rigidly locking the rungs to the side rails so as to eliminate any play therebetween.

It will be appreciated, that each plug it, in relation to its side rail member or plate 53, may be viewed as a stud-like element arranged in the opening of its rail member to project from the inner face thereof. Each plug has a shoulder positioned intermediate its ends to abut the inner face of said rail member or plate It and is flared beyond that shoulder to provide another shoulder having tight engagement with the outer face of its rail member l3. In this way the rail member is clamped rigidly between the inner shoulder and the outwardly flared shoulder 20.

It should be understood that the ladder sections l B constructed in accordance with the invention, may be used singly or, alternatively, several sections may be combined together to form what is commonly referred to as an extension ladder.

This structure is shown in the accompanying Figures 1, 2 and 3, wherein the ladder sections are positioned adjacent one another and each successive section is of relatively lesser width, in order that it may be receivable within the spacing of the side rails H of the section immediately.

adjacent thereto.

The several sections are, of course, relatively slidable, and suitable brackets 2| may be employed for guiding the sliding movement of the same.

Convenient means is employed for locking the sections together, such as is shown in the drawings by the conventional locking frames 22.

As will be apparent from the foregoing description and drawings, the unique simplicity of the invention is achieved primarily by the selection of weight-saving, yet durable parts, the same being particularly exemplified by the tubular elements H and I3 and by the formation of the side rails i I. The angles 12 may be of extruded form, and the Weight-saving characteristics of the ladder are further efiected by selection of suitable light-Weight materials such as aluminum, dural, magnesium alloy, or the like, from which the invention may be constructed in its entirety.

While in the foregoing there has been shown and described the preferred embodiment of this invention it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

What I claim as my invention is:

1. In a ladder structure of the class described, a tubular rung open at the ends thereof, a tubular plug in each end of said rung, a rivet extending transversely through said rung and through said plug, a portion of said plug protruding from the end of said rung, and a gusset plate formed with a countersunk aperture adapted to receive the protruding end of said plug, said protruding end being flared into the countersink of said aperture and peened over against the surface of said plate, said plate being associated with the side rail of the ladder.

2. The device as defined in claim 1, in which said side rail of the ladder comprises in combination, a pair of extended angles arranged in a spaced parallel relationship, a plurality of rivets securing said gusset plate to one arm of each of said angles, said angles and said plate defining a U-shaped cross-sectional configuration.

3. In a ladder structure of the class described: a pair of side rails; tubular rungs engaging said side rails at their ends in abutting relation; plugs in the ends of each rung secured to said rungs and extending through apertures in said side rails, the outer ends of said plugs being flared to clamp said side rails between said respective rungs and plugs.

4. A ladder structure as described in claim 3, wherein said plugs are in the form of hollow nipples.

5. In a ladder structure of the class described:

a pair of side rails each made up of a pair of spaced bars and having webs with apertures therein and uniting said bars at intervals; tubular rungs engaging said webs at their ends in abutting relation; plugs in the ends of each rung secured to said rungs and extending through the apertures in said webs, the outer ends of said plugs being flared to clamp said side rails between said respective rungs and plugs.

65. In a ladder construction: a side rail member having inner and outer faces and an opening extending through it from one face to the other; a stud-like plug arranged in said opening to project from the inner face of said rail member, said plug having a shoulder positioned intermediate its ends to abut the inner face of said member and being flared beyond the shoulder soas to clamp said rail member rigidly between said shoulder and said flare; and a rung rigidly secured to the projecting portion of the plug, said run being relatively long in relation to the plug and constructed separately therefrom.

7. The construction of claim 6 wherein: the rung is telescopically fitted to the projecting portion of the plug.

WILLIAM T. MASON.

' nsrcasncus CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 523,898 Knox July 31, 1894 683,250 Cowardin Sept. 24, 1901 848,114 Medart Mar. 26, 1907 857,453 Fetta June 18, 1907 869,959 Bryant Nov. 5, 1907 983,213 Dahill et al Jan. 81, 1911 1,136,010 Hendricks et al. Apr. 20, 1915 1,949,972 Murphy Mar. 6, 1934 2,040,977 Carbis May 19, 1936 2,126,171 Carbis Aug. 9, 1938 2,228,525 Lundskow Jan. 14, 1941 FOREIGN PATENTS Number Country Date 100,807 Australia Apr. 14, 1937 579,252 Germany June 22, 1933 

